Description

Everybody knows that water supply becomes an availability issue soon. But nobody seems to know how to save and nobody wants to miss a shower, mostly twice a day. My joke answer to a sales man, promoting water saving pipe reducers who claim to save up to 50% was, I know how to save 90 % - by showering once a week only. This was by the way not the spark, leading to the following water and energy saving project, short the shower project.
Some serious facts:
An average shower takes about 10 minutes. During this shower, about 100 liter warm water is drained into sewage, meaning, its not just water but also around 2500 Watt in energy, drained in order to keep a comfortable temperature.
I repeat: 100 liter water and 2500 watt energy (usually electricity) per shower session.
If your average family has 4 members and everybody is used to shower twice a day the formula 100 (liter) x4 (persons) x2 (courses per day) = 800 liter (or 0.8 Kl) plus 2500 (watt) x4 (persons) x2 (courses per day) = 20.000 watt (or 20 Kw) applies. Per day!
Which is per months 0.8 Kl x 30 (days) = 24 Kl and 20 Kw x 30 (days) = 600 Kw energy.
Or per year: 24 Kl x 12 (months) = 288 Kl water, and 600 x 12 (months) = 7.200 Kw energy.
How is that calculated?
Easy, increasing the temperature on 1 liter water by 1 degree (C) requires 1 watt power, per 100 liter accordingly 100 Watt or 0.1 Kilowatt (kw). The average difference between supplied cold water (10 deg. C) and warm water (35 deg. C) is 25 deg. C, 25 (deg. C) x100 (watt) = 2500 (watt) or 2.5 Kw.
I know, officially we measure even water in Kg’s (but its similar to liter), heating up 1 Kg water by 1 deg. C requires 4,2 kJ (kilo-Joules) = 0,001167 kWh = 1,167 W/h (Watt-hour Energy) and not Watt power. My way to explain is easier as I calculated without the time factor, but the consumption on the electricity bill is finally the same.

Is it worth to think about?
I initiated and developed the shower project based on the above facts with the goal to save not 10 or 20 or even 50 % water, the final calculation in saving comes 93-94% in water and energy. How?
Basically by circulating and purifying just 5 liter water per shower session. On the energy site, the saving comes just by maintaining the once off heated water. The counter calculation is as follows:
If your average family has 4 members and everybody is used to shower twice a day the formula 5 (liter) x4 (persons) x2 (courses per day) = 40 liter (verses 800 liter) 150 (watt) x4 (persons) x2 (courses per day) = 1.200 watt (verses 20.000 watt) applies. Per day!
Which is per months: 40 liter x 30 (days) = 1.2 Kl, and 1.2 Kw x 30 (days) = 36 Kw energy (The energy bill can be supported or even replaced by solar thermo and photo voltaic elements).
Or per year: 1.2 Kl x 12 (months) = 14.4 Kl water, and 36 x 12 (months) = 432 Kw energy.
Facts and Solutions:
Preparing hot water for hygienic purposes, washing and ironing, cooking and heating (in winter) are the biggest household energy consumers. Lights can nowadays be replaced by energy saving LED technology and solar geysers also contribute to lower electricity consumption, starting unfortunately only some hours after sunrise and don’t influence the water consumption.
By the way, losses through water heating by conventional geyser systems are not calculated.
Interim water storage:
Used and contaminated water can be reused, for instance to flush a toilet, and rainwater can be collected to run the fresh water supply, which is not drinking water anyway but clean enough for hygiene purposes. In all mobile applications like events, disaster management or in rural areas without tap water supply and sewage, fresh and used water (including toilet) can be pumped in and out mobile tanks, e.g. mounted on a trailer.
Portable/mobile sanitary room:
For all mobile and temporary applications, a foldable and light weight container can be supplied in different sizes according requirements. They are made from alumin